On his 70th birthday, an old man received a coupon from his wife...

The coupon paid for a visit to a medicine man living on a nearby reservation who was rumored to have a wonderful cure for erectile dysfunction.
After being persuaded to go, he drove to the reservation, handed his ticket to the medicine man and wondered what he was in for.
The old man handed a potion to him, and with a grip on his shoulder, warned, "This is a powerful medicine. You take only a teaspoon and then say '1-2-3'." When you do, you will become more manly than you have ever been in your life and you can perform as long as you want."
The man was encouraged. As he walked away, he turned and asked, "How do I stop the medicine from working?"
"Your partner must say '1-2-3-4,'" the medicine man responded, "but when she does, the medicine will not work again until the next full moon."
The man was very eager to see if it worked so he went home, showered, shaved, took a spoonful of the medicine and then invited his wife to join him in the bedroom. When she came in, he quickly took off his clothes and said, "1-2-3!" Immediately, he was the manliest of men. His wife was excited and began throwing off her clothes as she asked "What was the 1-2-3 for?"
And that, boys and girls, is why we should never end our sentences with a preposition, because we could end up with a dangling participle.